#ifndef QUERY_BASE_H
#define QUERY_BASE_H
#include<iostream>
class Query;
class QueryResult;
class TextQuery;
class Query_base {
    friend class Query;
protected:
    virtual ~Query_base() = default;
private:
    virtual QueryResult eval(const TextQuery&) const = 0;
    virtual std::string rep() const = 0;
    
};
#endif //QUERY_BASE_H